U.S. Air Force Airmen 1st Class Matthew Edquid, 633rd Logistics Readiness Squadron material management apprentice, and Jordan Rushing, a 633rd Civil Engineer Squadron geo-base apprentice, receive medical treatment in an ambulance during an active shooter exercise at Langley Air Force Base, Va., Dec. 8, 2011. The exercise helped to prepare 633rd Air Base Wing personnel for future exercises and potential real-world situations. (U.S. Air Force photo by Staff Sgt. Antoinette Gibson/Released)